remove plugin admin menu in wordpress without installing plugin in v3.8.1

add_action('admin_menu', 'remove_wpseo_admin_menu_links');

function remove_wpseo_admin_menu_links(){

remove_action( 'admin_bar_menu', 'wpseo_admin_bar_menu', 95 );

remove_menu_page( 'wpseo_dashboard' );


}